CA1157277A - Production of vermicular graphite cast iron - Google Patents
Production of vermicular graphite cast ironInfo
- Publication number
- CA1157277A CA1157277A CA000364437A CA364437A CA1157277A CA 1157277 A CA1157277 A CA 1157277A CA 000364437 A CA000364437 A CA 000364437A CA 364437 A CA364437 A CA 364437A CA 1157277 A CA1157277 A CA 1157277A
- Authority
- CA
- Canada
- Prior art keywords
- calcium
- rare earth
- iron
- added
- weight
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/08—Manufacture of cast-iron
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/08—Making cast-iron alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
Abstract
A B S T R A C T
Vermicular graphite cast iron is produced by adding to molten iron simultaneously up to 0.3% by weight of the iron of one or more rare earth metals and in excess of 0.2% by weight of the iron of calcium, the quantity of rare earth metal being within the range of 2 to 8 times the sulphur content of the molten iron.
The rare earth may be added for example as cerium, mischmetall or as rare earth silicide. The calcium may be added for example as calcium metal or as calcium silicide or a nickel-calcium alloy. An alloy containing both rare earth and calcium, such as a calcium-cerium-silicon alloy, or a composition containing rare earth, calcium and a fluxing agent may also be used.
Vermicular graphite cast iron is produced by adding to molten iron simultaneously up to 0.3% by weight of the iron of one or more rare earth metals and in excess of 0.2% by weight of the iron of calcium, the quantity of rare earth metal being within the range of 2 to 8 times the sulphur content of the molten iron.
The rare earth may be added for example as cerium, mischmetall or as rare earth silicide. The calcium may be added for example as calcium metal or as calcium silicide or a nickel-calcium alloy. An alloy containing both rare earth and calcium, such as a calcium-cerium-silicon alloy, or a composition containing rare earth, calcium and a fluxing agent may also be used.
Description
1 ~5~277 PR~DUCTION OF VERM ULAR GRA_HITE _AST_IRON
The invention relates to the production of vermicular gr3phite cast iron.
The term venmicular graphite cast irDn i5 used to denote cast iron in which flake graphite as been modified to a rounded, shorter fonm compared with the graphite in normal grey cast iron. This modified fonm of graphite is also known by other names, including "quasi-flake"and "compacted".
Vermicular graphite cast iron m3y be produced by treating molten iron with magnesium in conjunction with titanium 1û and one or m~re rare earth metals. Usually the magnesium is added as a 5~ magnesium ferrDsilicon containing cerium and titanium is added as ferrotitanium or titanium metal.
However it can be difficult to produce the correct graphite structure when making separate additions of the magnesium, titanium and rare earth metal, and an iron containing excessive titanium or an iron which has a nodular graphite structure due to the presence of insufficient titanium for the quantity of magnesium present can easily result.
These difficulties can be overcome by using special alloys containing magnesium, titanium and rare earth metals.
and Dritish Patent 1 427 445 describes the production and use of such alloys.
Dritish Patent 1 515 201 describes a modified alloy of the type disclosed in 1 427 445 which in addition contains calcium. The presence of the calcium gives an alloy which, for a given added quantity, produces a vermicular graphite structure over a wider range of initial sulphur contents in ~P
1 157~77
The invention relates to the production of vermicular gr3phite cast iron.
The term venmicular graphite cast irDn i5 used to denote cast iron in which flake graphite as been modified to a rounded, shorter fonm compared with the graphite in normal grey cast iron. This modified fonm of graphite is also known by other names, including "quasi-flake"and "compacted".
Vermicular graphite cast iron m3y be produced by treating molten iron with magnesium in conjunction with titanium 1û and one or m~re rare earth metals. Usually the magnesium is added as a 5~ magnesium ferrDsilicon containing cerium and titanium is added as ferrotitanium or titanium metal.
However it can be difficult to produce the correct graphite structure when making separate additions of the magnesium, titanium and rare earth metal, and an iron containing excessive titanium or an iron which has a nodular graphite structure due to the presence of insufficient titanium for the quantity of magnesium present can easily result.
These difficulties can be overcome by using special alloys containing magnesium, titanium and rare earth metals.
and Dritish Patent 1 427 445 describes the production and use of such alloys.
Dritish Patent 1 515 201 describes a modified alloy of the type disclosed in 1 427 445 which in addition contains calcium. The presence of the calcium gives an alloy which, for a given added quantity, produces a vermicular graphite structure over a wider range of initial sulphur contents in ~P
1 157~77
- 2 - FS 1143 the iron compared with an alloy containing no calcium. In thin section castings tless than 5 m~) treatment with magnesium and titanium gives unacceptable quantities of nodules and insufficient compacted graphite when the iron is well inoculated.
It has also bsen proposed to prDduce vermicular graphite iron by adding to molten iron one or more rare earth metals, ~or example cerium or mischmetall, which is a mixture of cerium and other rare earth metals. A process using rare earth metals is described in ~ritish Patent 1 26a 706. However as is stated in that patent when using rare earth metals alone it is necessary first to desulphurise the molten iron to an abnonmally low level or to use a large quantity of rare earth metal in order to obtain a fully vermicular graphite structure, Further, the use of rare earth metals alone is confined to the treatment of hypereutectic irons.
It has now been found that vermicular graphite iron may be produced from molten irons having a wide range of sulphur contents without the need for a preliminary desulphur-isation treatment, by the simultaneous addition of a rare earth metal and calcium, providing the additions of rare earth metal and calcium are kept within certain parameters.
According to the invention there is provided a process for treating molten iron containing carbon and sulphur to produce a cast iron having a vsnmicular graphite structure comprising adding to the molten iron simultaneously up to 0.3%
by weight of the iron of one or more rare earth metals and in excess of û.2% by weight of the iron of calcium ths quantity of rare earth metal being within the range of 2 to 8 times the sulphur content of the molten iron.
Preferably the iron contains less than 0.05% by weight ~ 3 ~ FS 1143 sulphur before treatmentiotherh~ise excessive dross m~y be ~ormsd in ths iron during the treatment process.
If the ratio of the rare earth metal added to the sulphur content of the metal b~fore treabmsnt exceeds 0:1 the graphite is present in the cast iron mainly as spheroids or nodules, and there is also a tendency for carbides to be produced even though the form of the graphite may be good.
When the ratio of rare earth metal to sulphur is very high~
for example of ths order of 1B:1, a fully white iron is produced.
When the calcium addition i5 about 0.2% by weight or below-the fonmation of flake graphite is promoted. Normally the amount of calcium added will not exceed about 0.7% by weight.
In general for a particular sulphur content the lower the quantity of calcium which is added thæ higher the quantity of rare earth metal added, and vice versa.
Preferably the quantity of calcium added is in the range of 0.25-0.7% by weight of the iron and the rare earth 2û metal to sulphur ratio is in the range of 2.0-5.û.
Provided that the rare earth metal and the calcium are added to the molten iron simultaneously they may be added either as separate additions or in adnixture.
The rare earth metal may be a pure metal such as cerium or a mixture of rare earth metals in the fonm of mischmetall may be used. Mischmetall is a rare earth alloy containing 99.5% rare earths of which 49.5% is cerium. The rare earth may also be added in the fonm of a rars earth silicide.
' .... .....
1 ~S72'~7 ~ 4 ~ FS 1143 Ths calcium maV be added as calcium metal but the calcium is pre~erably added as an alloy, for example as calcium silicide or as a nicksl-calcium alloy.
Alternatively calcium, cerium and silicon may be alloyed together and the addition made in this way. When such an alloy is used it may be necessary to add additional calcium, for example as calcium ~ilicide~ to achieve the desired calcium addition rate.
Particularly when the calcium is added as calcium silicide it may be desirable to also add a fluxing agent, such as calcium fluor;de, to improve the dissolution of the calcium in the molten iron.
According to a further feature of the invention there-fors there is provided a composition for use in the production of vermicular graphite iron which comprises one or nore rare earth mstals, calcium and a fluxing agent.
Usually the composition will contain 1.5-10% by weight of rare earth metal, 15-35% by weight of calcium and 6-10% by weight of fluxing agent, the remainder being iron and silicon, 2D acting as carriers.
The rare earth metal, calcium and fluxing agent may-be mixed together and compacted to fonm briquettes, tablets or pellets to facilitate adding the composition to the molt~n iron, or the rare earth metal and calcium may be alloyed~ The flux is then mixed with ths alloy.
After treatment with ths rare earth metal and calcium ths iron is treated with an inoculant ~uch as fsrrosilicon in the normal way prior to casting.
~, .
~ .
.. . . . , . ~ . , ~ 1~7~77 The process and composition of the invention offer a numbsr of advantages over existing processes and compositions which are used to produce vermicular graphite cast iron:-1. ~y adding calcium simultaneously with cerium or other rare earth metal it is possible to reduce the amount of rare earth metal added considerably. As little as one fifth of the usual rare earth addition may be needed when calcium is added as well, and since it would be usual to add rare earth at a rate of at least 10 times the inital sulphur content when using rare earth alone the saving in rare earth metal is appreciable.
2. The use of a combination of calcium and rars earth metal gives results which are less sensitive to the differences in casting section thickness than processes using magnesium and titanium, and there is less tendency to produce undes-irable nodular graphite structures.
It has also bsen proposed to prDduce vermicular graphite iron by adding to molten iron one or more rare earth metals, ~or example cerium or mischmetall, which is a mixture of cerium and other rare earth metals. A process using rare earth metals is described in ~ritish Patent 1 26a 706. However as is stated in that patent when using rare earth metals alone it is necessary first to desulphurise the molten iron to an abnonmally low level or to use a large quantity of rare earth metal in order to obtain a fully vermicular graphite structure, Further, the use of rare earth metals alone is confined to the treatment of hypereutectic irons.
It has now been found that vermicular graphite iron may be produced from molten irons having a wide range of sulphur contents without the need for a preliminary desulphur-isation treatment, by the simultaneous addition of a rare earth metal and calcium, providing the additions of rare earth metal and calcium are kept within certain parameters.
According to the invention there is provided a process for treating molten iron containing carbon and sulphur to produce a cast iron having a vsnmicular graphite structure comprising adding to the molten iron simultaneously up to 0.3%
by weight of the iron of one or more rare earth metals and in excess of û.2% by weight of the iron of calcium ths quantity of rare earth metal being within the range of 2 to 8 times the sulphur content of the molten iron.
Preferably the iron contains less than 0.05% by weight ~ 3 ~ FS 1143 sulphur before treatmentiotherh~ise excessive dross m~y be ~ormsd in ths iron during the treatment process.
If the ratio of the rare earth metal added to the sulphur content of the metal b~fore treabmsnt exceeds 0:1 the graphite is present in the cast iron mainly as spheroids or nodules, and there is also a tendency for carbides to be produced even though the form of the graphite may be good.
When the ratio of rare earth metal to sulphur is very high~
for example of ths order of 1B:1, a fully white iron is produced.
When the calcium addition i5 about 0.2% by weight or below-the fonmation of flake graphite is promoted. Normally the amount of calcium added will not exceed about 0.7% by weight.
In general for a particular sulphur content the lower the quantity of calcium which is added thæ higher the quantity of rare earth metal added, and vice versa.
Preferably the quantity of calcium added is in the range of 0.25-0.7% by weight of the iron and the rare earth 2û metal to sulphur ratio is in the range of 2.0-5.û.
Provided that the rare earth metal and the calcium are added to the molten iron simultaneously they may be added either as separate additions or in adnixture.
The rare earth metal may be a pure metal such as cerium or a mixture of rare earth metals in the fonm of mischmetall may be used. Mischmetall is a rare earth alloy containing 99.5% rare earths of which 49.5% is cerium. The rare earth may also be added in the fonm of a rars earth silicide.
' .... .....
1 ~S72'~7 ~ 4 ~ FS 1143 Ths calcium maV be added as calcium metal but the calcium is pre~erably added as an alloy, for example as calcium silicide or as a nicksl-calcium alloy.
Alternatively calcium, cerium and silicon may be alloyed together and the addition made in this way. When such an alloy is used it may be necessary to add additional calcium, for example as calcium ~ilicide~ to achieve the desired calcium addition rate.
Particularly when the calcium is added as calcium silicide it may be desirable to also add a fluxing agent, such as calcium fluor;de, to improve the dissolution of the calcium in the molten iron.
According to a further feature of the invention there-fors there is provided a composition for use in the production of vermicular graphite iron which comprises one or nore rare earth mstals, calcium and a fluxing agent.
Usually the composition will contain 1.5-10% by weight of rare earth metal, 15-35% by weight of calcium and 6-10% by weight of fluxing agent, the remainder being iron and silicon, 2D acting as carriers.
The rare earth metal, calcium and fluxing agent may-be mixed together and compacted to fonm briquettes, tablets or pellets to facilitate adding the composition to the molt~n iron, or the rare earth metal and calcium may be alloyed~ The flux is then mixed with ths alloy.
After treatment with ths rare earth metal and calcium ths iron is treated with an inoculant ~uch as fsrrosilicon in the normal way prior to casting.
~, .
~ .
.. . . . , . ~ . , ~ 1~7~77 The process and composition of the invention offer a numbsr of advantages over existing processes and compositions which are used to produce vermicular graphite cast iron:-1. ~y adding calcium simultaneously with cerium or other rare earth metal it is possible to reduce the amount of rare earth metal added considerably. As little as one fifth of the usual rare earth addition may be needed when calcium is added as well, and since it would be usual to add rare earth at a rate of at least 10 times the inital sulphur content when using rare earth alone the saving in rare earth metal is appreciable.
2. The use of a combination of calcium and rars earth metal gives results which are less sensitive to the differences in casting section thickness than processes using magnesium and titanium, and there is less tendency to produce undes-irable nodular graphite structures.
3. Treatment of molten iron with a calcium - rare earth composition produces a quiet reaction unlike that of mag-nesium which give rise to flaring and bubbling of the molten iron.
4. Scrap iron e.g. casting runners and risers resulting from the process can be remelted without the need to take any special precautions. In a foundry producing both nodular iron and vermicular graphits iron castings, and using the magnesium-titanium process to produse the latter, it would be necessary to segregate any scrap containing titanium to prevent it being ramelted and used for nodular iron production.
The following examples will serve to illustrate the invention:-l 1~7277 A charge of pig iron and steel scrap was melted and a sample taken for chemical analysis. The sulphur content oF
the iron was detenmined as 0.051% by weight. The molten iron was heated to 1550C and 72kg was tapped on to a mixture of 0.2% by weight based on the weight of the iron of mischmetall and 1.6% by weight based on the weight of the iron of calcium silicide in a hand ladle. Slag was removed from the iron which W35 then transferred to a second hand ladle, 0.5% by weight on the weight of the iron of ferrosilicon being added to inoculate the iron during the transfer process. The treated iron was then cast at 1450C into a green sand mould and the casting produced was sectioned and its microstructure examined. The casting had a ven~icular or compacted graphite structure and a matrix structure of pearlite and ferrite haloes.
A similar result was obtained using 1.9% by weight of calcium silicide instead of 1.6%.
EX~MPLE Z
The procedure of Example 1 was repeated except that the iron had a sulphur content of 0.056% and 0.16% by weight based on the weight of iron treated of calcium fluoride was included as a fluxing agent to aid dissolution of the calcium silicide.
The oast iron produced had a venmicular graphite structure with a pearlitic matrix.
Using the procedure of Example 1 molten iron having 3 1~7277 a low sulphur content (0.011%) was treated with 1.5% calcium silicide, 0.19% calcium fluoride and 0.04% mischmetall, followed by 0.5% ferrosilicon tall percenta~es by weight ba~ed on the weight of iron treated).
A cast iron having a vermicular graphite structure and a matrix consisting of 70% ferrite and 30% pearlite was produced.
Using the.procedure of Example 1 various iron melts were treated using compositions based in some cases on mischmetall and calcium silicide and in other cases on calcium, cerium and silicon alloys.
The sulphur content of the molten iron varied from 0.008% to 0.056% and the ratio of rare earth metal added to sulphur contsnt varied from 1.79 to 25Ø The quantity of calcium added varied from 0.16% to 0.53%.
The results obtained are tabulated below:
No. Initial Rare Earths RE Calcium Graphite Matrix Sulphur tRE) Added S Added t%) Form Ferrite %/
(S) (%) (%) Pearlite %
.. , ... .. . , . ~
1 0.013 0.051 3.92 0.16 Coarse 70/30 Flake 2 0.013 û.053 4.08 0.20 Undercooled 90/10 Flake 3 0.013 0.055 4.23 0.24 Vermicular 60~40 4 0,û13 0.054 4.15 0.27 Vermicular 60~40 0,013 0.052 4.06 û.36 Vermicular. 50~50 - e - FS 114:3 No. Initial Rare Earths RE Calcium Graphite @atriit ~/
S lphur (RE) Ad~ed S Added (%) Forrn Ps rlits 6 0.013 0.067 5.15 0.34 Vennicular 50/50 7 0.056 0.10 1.79 0.53 Coarse 0/100 Flake 8 0.056 0.20 ~.5B 0.53 Vermicular 2/98 9 0.008 0.20 25.0 0.51 NIL 100~ Fe3C
10 0.017 0.031 1.82 0.31 Fine Flake 95/5 11 0.017 0.042 2.47 0.32 Vermicular 60/40 12 0.009 0.154 17.1 0.53 Nodular 30/70 13 0.009 0.167 1a.6 0.53 NIL 100% Fe3C
Ircns Nos. 3-6, 8 and 11 had all been treated according to the process of the invention and all had vermicular graphite stn~ctures. The remainder, which were not produced by the process of the invention did not contain venTicular graphite.
EXAMPLE_ 5 In a foundry pr~duction trial 360 kg of iron of 0.014%
sulphur was treated with a composition containing rare earth-calcium-silicon alloy plus calcium silicide to give a calcium addition to the imn of 0.45% and a rare ea~th addition of 0.11%
(i.e. a rare earth/sulphur ratio of a:1), followed by an inoculation with 0.8% to FeSi. Several complex, highly-cored multi-spool hydraulic valve bodies were cast. These intricate castings contain complsx intemal passageways and have a variety of interconnected sections, varying in thickness frcm 5 mm to 30 rrm, each casting weighing about 9 kg.
1 157~77 ~ 9 ~ FS 1143 Some randomly selected castings were cleaned and sectioned and the microstructures of the sections were examined. The structures were as shown below, indicating that change in section thickness had little effect on the graphite fonm.
S Section Graphite Matrix Thickness ~mm) Ferrite %/Pearlite %
_ _ Venmicular 60/40 8 Venmicular 70/~0 Venmicular + 90/10
The following examples will serve to illustrate the invention:-l 1~7277 A charge of pig iron and steel scrap was melted and a sample taken for chemical analysis. The sulphur content oF
the iron was detenmined as 0.051% by weight. The molten iron was heated to 1550C and 72kg was tapped on to a mixture of 0.2% by weight based on the weight of the iron of mischmetall and 1.6% by weight based on the weight of the iron of calcium silicide in a hand ladle. Slag was removed from the iron which W35 then transferred to a second hand ladle, 0.5% by weight on the weight of the iron of ferrosilicon being added to inoculate the iron during the transfer process. The treated iron was then cast at 1450C into a green sand mould and the casting produced was sectioned and its microstructure examined. The casting had a ven~icular or compacted graphite structure and a matrix structure of pearlite and ferrite haloes.
A similar result was obtained using 1.9% by weight of calcium silicide instead of 1.6%.
EX~MPLE Z
The procedure of Example 1 was repeated except that the iron had a sulphur content of 0.056% and 0.16% by weight based on the weight of iron treated of calcium fluoride was included as a fluxing agent to aid dissolution of the calcium silicide.
The oast iron produced had a venmicular graphite structure with a pearlitic matrix.
Using the procedure of Example 1 molten iron having 3 1~7277 a low sulphur content (0.011%) was treated with 1.5% calcium silicide, 0.19% calcium fluoride and 0.04% mischmetall, followed by 0.5% ferrosilicon tall percenta~es by weight ba~ed on the weight of iron treated).
A cast iron having a vermicular graphite structure and a matrix consisting of 70% ferrite and 30% pearlite was produced.
Using the.procedure of Example 1 various iron melts were treated using compositions based in some cases on mischmetall and calcium silicide and in other cases on calcium, cerium and silicon alloys.
The sulphur content of the molten iron varied from 0.008% to 0.056% and the ratio of rare earth metal added to sulphur contsnt varied from 1.79 to 25Ø The quantity of calcium added varied from 0.16% to 0.53%.
The results obtained are tabulated below:
No. Initial Rare Earths RE Calcium Graphite Matrix Sulphur tRE) Added S Added t%) Form Ferrite %/
(S) (%) (%) Pearlite %
.. , ... .. . , . ~
1 0.013 0.051 3.92 0.16 Coarse 70/30 Flake 2 0.013 û.053 4.08 0.20 Undercooled 90/10 Flake 3 0.013 0.055 4.23 0.24 Vermicular 60~40 4 0,û13 0.054 4.15 0.27 Vermicular 60~40 0,013 0.052 4.06 û.36 Vermicular. 50~50 - e - FS 114:3 No. Initial Rare Earths RE Calcium Graphite @atriit ~/
S lphur (RE) Ad~ed S Added (%) Forrn Ps rlits 6 0.013 0.067 5.15 0.34 Vennicular 50/50 7 0.056 0.10 1.79 0.53 Coarse 0/100 Flake 8 0.056 0.20 ~.5B 0.53 Vermicular 2/98 9 0.008 0.20 25.0 0.51 NIL 100~ Fe3C
10 0.017 0.031 1.82 0.31 Fine Flake 95/5 11 0.017 0.042 2.47 0.32 Vermicular 60/40 12 0.009 0.154 17.1 0.53 Nodular 30/70 13 0.009 0.167 1a.6 0.53 NIL 100% Fe3C
Ircns Nos. 3-6, 8 and 11 had all been treated according to the process of the invention and all had vermicular graphite stn~ctures. The remainder, which were not produced by the process of the invention did not contain venTicular graphite.
EXAMPLE_ 5 In a foundry pr~duction trial 360 kg of iron of 0.014%
sulphur was treated with a composition containing rare earth-calcium-silicon alloy plus calcium silicide to give a calcium addition to the imn of 0.45% and a rare ea~th addition of 0.11%
(i.e. a rare earth/sulphur ratio of a:1), followed by an inoculation with 0.8% to FeSi. Several complex, highly-cored multi-spool hydraulic valve bodies were cast. These intricate castings contain complsx intemal passageways and have a variety of interconnected sections, varying in thickness frcm 5 mm to 30 rrm, each casting weighing about 9 kg.
1 157~77 ~ 9 ~ FS 1143 Some randomly selected castings were cleaned and sectioned and the microstructures of the sections were examined. The structures were as shown below, indicating that change in section thickness had little effect on the graphite fonm.
S Section Graphite Matrix Thickness ~mm) Ferrite %/Pearlite %
_ _ Venmicular 60/40 8 Venmicular 70/~0 Venmicular + 90/10
5% nodules
Claims (15)
1. A process for treating molten iron containing carbon and sulphur to produce a cast iron having a vermicular graphite structure comprising adding to the molten iron simultaneously up to 0.3% by weight of the iron of one or more rare earth metals and in excess of 0.2% by weight of the iron of calcium the quantity of rare earth metal being within the range of 2 to 3 times the sulphur content of the molten iron.
2. A process according to claim 1 in which the amount of calcium added does not exceed 0.7% by weight of the iron.
3. A process according to claim 1 in which the amount of rare earth metal added is within the range of 2-5 times the sulphur content of the molten iron.
4. A process according to claim 1 in which the rare earth metal is added as mischmetall or rare earth silicide.
5. A process according to claim 1 in which the calcium is added as calcium silicide or a nickel-calcium alloy.
6. A process according to claim 1 in which the rare earth metal and at least part of the calcium are added as a cerium-calcium-silicon alloy.
7. A process according to any of claims 1, 2 or 3 in which a fluxing agent is also added in order to improve the dissolution of the calcium.
8. A process according to claims 4, 5 or 6 in which a fluxing agent is also added in order to improve the dissolution of the calcium.
9. A composition for use in the process of claim 1 comprising 1.5% - 10% by weight of rare earth metal, 15% -35% by weight of calcium, and 6% - 10% by weight of a fluxing agent, the balance being iron and silicon, serving as carriers.
10. A composition according to claim 9 in which the rare earth metal is present as mischmetall or rare earth silicide.
11. A composition according to claim 9 in which the calcium is present as calcium silicide or a nickel-calcium alloy.
12. A composition according to claim 9 in which the rare earth metal and at least part of the calcium are present as a cerium-calcium-silicon alloy.
13. A composition according to claim 9 in which the fluxing agent is calcium fluoride.
14. A composition according to any one of claims 10, 11 or 12 in which the fluxing agent is calcium fluoride.
15. A process according to claim 2 in which the amount of calcium added is in the range of 0.25% - 0.7%
by weight of the iron.
by weight of the iron.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7943698 | 1979-12-19 | ||
| GB7943698 | 1979-12-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1157277A true CA1157277A (en) | 1983-11-22 |
Family
ID=10509935
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000364437A Expired CA1157277A (en) | 1979-12-19 | 1980-11-12 | Production of vermicular graphite cast iron |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4430123A (en) |
| EP (1) | EP0041953B1 (en) |
| JP (1) | JPS6044369B2 (en) |
| BR (1) | BR8008987A (en) |
| CA (1) | CA1157277A (en) |
| DE (1) | DE3068244D1 (en) |
| ES (1) | ES8200924A1 (en) |
| IT (1) | IT1141640B (en) |
| WO (1) | WO1981001861A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59197345A (en) * | 1983-04-22 | 1984-11-08 | Osaka Tokushu Gokin Kk | Production of cv cast iron |
| NL1003408C2 (en) * | 1996-06-24 | 1998-01-07 | Rombout Adriaan Swanborn | Apparatus and method for treating a gas / liquid mixture. |
| SE529445C2 (en) * | 2005-12-20 | 2007-08-14 | Novacast Technologies Ab | Process for making compact graphite iron |
| EP1970460B1 (en) * | 2007-03-07 | 2009-01-21 | Eisenwerk Arnstadt GmbH | Cast iron for manufacturing parts for friction braking devices and method for producing the cast iron |
| CN103484751B (en) * | 2013-09-17 | 2015-12-23 | 蓬莱万寿机械有限公司 | A kind of method and application thereof preparing vermicular cast iron |
| US11859270B2 (en) | 2016-09-12 | 2024-01-02 | Snam Alloys Pvt Ltd | Non-magnesium process to produce compacted graphite iron (CGI) |
| CN110578031B (en) * | 2019-10-15 | 2021-10-26 | 中国重汽集团济南动力有限公司 | Pretreatment agent and pretreatment method for vermicular graphite cast iron molten iron |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2889222A (en) | 1953-12-30 | 1959-06-02 | Union Carbide Corp | Process for the production of nodular cast iron |
| JPS5112443B1 (en) | 1965-12-13 | 1976-04-20 | ||
| AT290592B (en) | 1968-05-03 | 1971-06-11 | Ver Fuer Praktische Giessereif | Process for the production of a cast iron with vermicular graphite |
| GB1515201A (en) | 1976-02-10 | 1978-06-21 | British Cast Iron Res Ass | Cast iron |
-
1980
- 1980-11-05 BR BR8008987A patent/BR8008987A/en unknown
- 1980-11-05 DE DE8080901968T patent/DE3068244D1/en not_active Expired
- 1980-11-05 WO PCT/GB1980/000193 patent/WO1981001861A1/en active IP Right Grant
- 1980-11-05 EP EP80901968A patent/EP0041953B1/en not_active Expired
- 1980-11-05 US US06/290,802 patent/US4430123A/en not_active Expired - Fee Related
- 1980-11-05 JP JP55502455A patent/JPS6044369B2/en not_active Expired
- 1980-11-12 CA CA000364437A patent/CA1157277A/en not_active Expired
- 1980-12-18 IT IT68937/80A patent/IT1141640B/en active
- 1980-12-18 ES ES497882A patent/ES8200924A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4430123A (en) | 1984-02-07 |
| JPS56501765A (en) | 1981-12-03 |
| WO1981001861A1 (en) | 1981-07-09 |
| ES497882A0 (en) | 1981-11-16 |
| EP0041953B1 (en) | 1984-06-13 |
| ES8200924A1 (en) | 1981-11-16 |
| EP0041953A1 (en) | 1981-12-23 |
| BR8008987A (en) | 1981-10-20 |
| IT1141640B (en) | 1986-10-01 |
| JPS6044369B2 (en) | 1985-10-03 |
| IT8068937A0 (en) | 1980-12-18 |
| DE3068244D1 (en) | 1984-07-19 |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |